In an automotive air-conditioning system, the compressor pumps heat-laden refrigerant from the evaporator, and compresses the refrigerant, sending it, under high pressure, to the condenser as a superheated vapor. Since the high pressure vapor delivered to the condensor is much hotter than the surrounding air, it gives up its heat to the outside air flowing through the condenser fins.
As the refrigerant vapor gives up its heat, it changes to a liquid. The condensed liquid refrigerant is filtered, dried and temporarily stored under pressure, in the receiver-drier, also known as the "accumulator dehydrator", until it is needed by the evaporator.
Liquid refrigerant is metered from the condenser into the evaporator by an orifice tube which controls the flow of refrigerant in the conditioning system. The orifice tube floods the evaporator with liquid refrigerant. In so doing, the liquid refrigerant picks up heat from the warm air passing through the fins of the evaporator. The warm liquid refrigerant boils into the accumulator dehydrator. The compressor then transmitts the warm dehydrated vapor to the condensor for dissipation.
The present invention is concerned particularly with the accumulator dehydrator or receiver-drier, which, as stated, is a part of the system that is used to store refrigerant. It is located in the low-pressure side of the air-conditioning system and for the most part, contains liquid refrigerant.
The accumulator dehydrator usually consists of a cylindrical metal can with inlet and outlet fittings and, in most cases a a sight glass. It may be divided into two parts: the receiver and the drier.
The accumulator section of the tank or can is a storage compartment to accept the proper amount of excess refrigerant the system requires to insure operation. It is function of the accumulator section to insure that a steady flow of vapor refrigerant is supplied to the compressor.
The dehydrator section of the tank or can is simply a bag of dessicant, such as molecular sieve, that is capable of absorbing and holding a small quantity of moisture.
A screen is placed in the dehydrator section to catch and hold any trash that may be in the system and prevent its circulation. Though this screen is not serviceable, the cleaned orifice tube that may be cleaned or replaced if necessary.